Three-jet cross sections in hadron-hadron collisions at next-to-leading order

TL;DR

It is shown that the next-to-leading order correction significantly reduces the renormalization and factorization scale dependence of the three-jet cross section.

Abstract

We present a new QCD event generator for hadron collider which can calculate one-, two- and three-jet cross sections at next-to-leading order accuracy. In this letter we study the transverse energy spectrum of three-jet hadronic events using the kT algorithm. We show that the next-to-leading order correction significantly reduces the renormalization and factorization scale dependence of the three-jet cross section.

Figures (4)

• Figure 1: Comparison of the $K$ factors of the one-jet inclusive cross section defined using the $k_\perp$ and for $\rm MRSD'_{-}$ parton densities obtained with Monte Carlo programs JETRAD and NLOJET++ (this work). The bands indicate the statistical error of the calculations.
• Figure 2: The perturbative prediction for the three-jet differential cross section in the term of the transverse energy of the leading jet at Born level (light gray band) and next-to-leading order (dark gray band). The bands indicate the theoretical uncertainty due to the variation of the renormalization and factorization scales $x_{R,F}$ between $0.5$ and $2$. The solid line is the NLO result for the $x_R = x_F = 1$ choice of the scales.
• Figure 3: The dependence of the three-jet cross section $\sigma_{\rm 3jet}$ on the renormalization and factorization scales.
• Figure 4: The dependence of the three-jet differential cross section on the parameter $D$. The $R_D$ means the ration of the differential cross sections for a given $D$ and for $D = 1$. Upper figure shows the Born level result and the lower figure shows the NLO prediction. The error bars indicate the statistical error of the Monte Carlo calculation.